PHP文件引入与参数传递：避免常见陷阱与最佳实践

<?php
function write_pdf($orientation, $initrow, $rowsperpage)
{
    ob_start(); // 开启输出缓冲

    // 直接在require之前定义变量，它们将在mypage.php中可见
    // 这里不需要通过URL查询字符串传递参数
    require "./mypage.php"; 

    $html = ob_get_clean(); // 获取缓冲内容

    // 假设Dompdf类已加载
    $dompdf = new Dompdf();
    $dompdf->loadHtml($html);
    // ... 后续Dompdf操作
    $dompdf->render();
    $dompdf->stream("document.pdf", array("Attachment" => false));
}

// 调用函数
write_pdf('P', 1, 20); 
?>

<?php
// 在这里，直接访问 $orientation, $initrow, $rowsperpage 变量即可
// 它们是从 main_script.php 的作用域中继承过来的
echo "Orientation: " . $orientation . "<br>";
echo "Initial Row: " . $initrow . "<br>";
echo "Rows Per Page: " . $rowsperpage . "<br>";

// 示例：生成一些HTML内容
?>
<h1>PDF Report</h1>
<p>This is a report generated with orientation: <?php echo $orientation; ?>, starting from row <?php echo $initrow; ?> and showing <?php echo $rowsperpage; ?> rows.</p>

<?php
function write_pdf($orientation, $initrow, $rowsperpage)
{
    ob_start();

    // 在require之前手动设置 $_GET 变量
    $_GET['orient'] = $orientation;
    $_GET['init'] = $initrow;
    $_GET['nrrows'] = $rowsperpage;

    require "./mypage_get.php"; 

    $html = ob_get_clean();

    $dompdf = new Dompdf();
    $dompdf->loadHtml($html);
    // ... 后续Dompdf操作
}

write_pdf('L', 10, 50);
?>

<?php
// 在这里，通过 $_GET 数组访问参数
$orientation = $_GET['orient'] ?? 'P'; // 使用 ?? 运算符提供默认值，避免Undefined index
$initrow = $_GET['init'] ?? 1;
$rowsperpage = $_GET['nrrows'] ?? 20;

echo "Orientation (from GET): " . $orientation . "<br>";
echo "Initial Row (from GET): " . $initrow . "<br>";
echo "Rows Per Page (from GET): " . $rowsperpage . "<br>";
?>
<h1>PDF Report (GET Method)</h1>
<p>Generated with orientation: <?php echo $orientation; ?>, starting from row <?php echo $initrow; ?> and showing <?php echo $rowsperpage; ?> rows.</p>

<?php
// 引入包含函数的PHP文件
require "./mypage_func.php"; 

function write_pdf($orientation, $initrow, $rowsperpage)
{
    ob_start();

    // 调用被引入文件中的函数，并直接传递参数
    generatePdfContent($orientation, $initrow, $rowsperpage); 

    $html = ob_get_clean();

    $dompdf = new Dompdf();
    $dompdf->loadHtml($html);
    // ... 后续Dompdf操作
}

write_pdf('P', 5, 30);
?>

<?php
/**
 * 生成PDF内容的函数
 *
 * @param string $orientation PDF方向 (P for Portrait, L for Landscape)
 * @param int $initrow 起始行号
 * @param int $rowsperpage 每页行数
 * @return void
 */
function generatePdfContent($orientation, $initrow, $rowsperpage)
{
    // 在函数内部，参数是局部变量，清晰且隔离
    echo "Orientation (from Function): " . $orientation . "<br>";
    echo "Initial Row (from Function): " . $initrow . "<br>";
    echo "Rows Per Page (from Function): " . $rowsperpage . "<br>";
    ?>
    <h1>PDF Report (Function Method)</h1>
    <p>Generated with orientation: <?php echo $orientation; ?>, starting from row <?php echo $initrow; ?> and showing <?php echo $rowsperpage; ?> rows.</p>
    <?php
}
?>

<?php
class PdfContentGenerator
{
    private $orientation;
    private $initrow;
    private $rowsperpage;

    public function __construct($orientation, $initrow, $rowsperpage)
    {
        $this->orientation = $orientation;
        $this->initrow = $initrow;
        $this->rowsperpage = $rowsperpage;
    }

    public function generateHtml()
    {
        ob_start();
        ?>
        <h1>PDF Report (Class Method)</h1>
        <p>Generated with orientation: <?php echo $this->orientation; ?>, starting from row <?php echo $this->initrow; ?> and showing <?php echo $this->rowsperpage; ?> rows.</p>
        <?php
        return ob_get_clean();
    }
}
?>

<?php
require "./mypage_class.php"; 

function write_pdf_class($orientation, $initrow, $rowsperpage)
{
    // 实例化类并传递参数
    $generator = new PdfContentGenerator($orientation, $initrow, $rowsperpage);
    $html = $generator->generateHtml(); // 调用方法获取HTML内容

    $dompdf = new Dompdf();
    $dompdf->loadHtml($html);
    // ... 后续Dompdf操作
}

write_pdf_class('L', 15, 40);
?>